code: def testFlat(self):
      self.assertEqual(FlatnessSFX()([0.5] * 100), 1.0)
  
file_path: essentia/test/src/unittests/sfx/test_flatnesssfx.py
imports: from essentia_test import *
  import numpy
label_desc: Use image node_id 4 for calling the TestFlatnessSfx obj's underlying member method code with example usage: obj.testFlat() without return types